1. Field of the Invention
The present invention relates to electric motors and more particularly to paper shredders having electric motors with cooling apparatus.
2. Background Art
Consumer product satisfaction is driven at a particular product price point by product safety, product reliability, and product longevity. This is particularly so in the field of consumer paper shredders, where a shredder can endure excessive or rough wear despite the non-industrial focus of the shredder product specifications. Such excessive or rough wear can, over time, degrade the reliability and longevity of the shredder product causing the consumer to become dissatisfied with the product. In some cases, repeated stresses on the moving parts of the shredder may cause part failure, leading to the expense of product repair or replacement, a further decrease in satisfaction, or even loss of goodwill for the respective consumer in the paper shredder brand. Even marginally stressful moments of operation may in the aggregate take their toll on the operating machinery of the shredder.
One shredder part which can be vulnerable to mechanical and thermal stresses is the shredder electric motor, which can arise from, for example, frequent starting, overloading, jamming, and continuous, beyond-rating use. Over time, the cumulative stresses faced by a shredder motor may lead to premature failure or poor performance. A common thread with these stressors is the heating effects of motor current (I2R losses). Many sophisticated electronic controllers have been devised to reduce the effects of I2R losses upon motors. Complex mechanical cooling systems have been advanced for large motors, as well. However, in the sphere of fractional-horsepower electric motors, as used in light- to medium-duty paper shredders, sophisticated electronic controllers and complex mechanical coolers can add prohibitive premiums to the motor cost, and to the cost to consumers, reducing a manufacturer's market share. An inexpensive but efficacious cooling apparatus for paper shredder motors is needed.